1,023 research outputs found
Use of Simplified Mathematical Formulations in Multi-phase Thermal Pump (MPTP) for Theoretical Prediction of Working Conditions
In this work mathematical expressions have been formed and solved to get predictions of working parameters of multiphase thermal pump (MPTP). MPTP is a simple pump which uses steam to pump water. The results have been compared with data found experimentally. Experimental and theoretical values for a range of pressures versus velocity differed by approximately 8.7% up 12% Through dimensional analysis dimensionless parameters were found Re, Eu, Fo and h/d pmp . These helped to further elucidate the pump’s pumping phenomenon. It was experimentally shown that the Reynolds number found theoretically gave limit of flow operating regime of the pump that it is in the transition regime. Above this the pump failed to operate. The Euler dimensionless number gave the dependency of interface velocity on pressure relation, when pressure was raised the velocity increased. The relation between the two parameters was found to be approximately quadratic. The Fourier dimensionless number gave the influence of heat transfer properties of the material of the pump to the operating characteristics. It was experimentally found that the influence of the overall heat transfer coefficient and heat transfer were the main driving forces behind the operation of the pump. Average interface velocities in the pump were found using pipe flow energy and mass conservation equations. Conditions for operation (pumping and suction) of the pump have been established based on the formed mathematical formulations
Pain clinic referral to psychological services best addressed with collaboration
A case study of a middle aged female with severe musculoskeletal medical conditions causing severe pain is presented. The referral for psychological services was conducted in concordance with the medical treatments. In this case, the complex nature of the severe musculoskeletal medical conditions necessitated intensive care and the collaborative communications provided this to the patient. A tabulation of representative treatments is provided with an explanation of the nature of the collaboration. Outcome data in terms of patient self-reported pain ratings and sleep logging provided evidence of a mild improvement and stability where more negative findings, given the complexity of the medical conditions was expected
Associations of blood pressure with body composition among Afro-Caribbean children in Barbados
Despite complex presentation of adult hypertension and a concomitant obesity epidemic, little is known about overweight in relation to blood pressure among Caribbean children. We examined blood pressure in relation to body size in a cross-sectional study of 573 Barbadian children aged 9–10 years (2010-2011).The United States normative blood pressure percentiles were used to identify children with high (≥ 95th percentile) or high normal blood pressure (90th – 95th percentile). The World Health Organization body mass index cut-off points were used to assess weight status.
Major findings:
Thirty percent of children were overweight/obese. Percentage fat mass differed between girls (20.4%) and boys (17.72%) (p< 0.05). Mean systolic blood pressure among girls was 106.11 (95% CI 105.05, 107.17) mmHg and 105.23 (104.09, 106.38) for boys. The percentages with high or high-normal mean systolic blood pressurewere14.38% (10.47, 18.29) for girls and 8.08% (4.74, 11.41) for boys. Height and body mass index were independent correlates of systolic and diastolic blood pressure. Mean systolic blood pressure was related to lean mass but not fat mass, while diastolic blood pressure was associated with fat mass index and overweight.
Principal conclusion:
One third of 9-10 year old children in Barbados were overweight/obese and 12% had elevated mean systolic blood pressure. BP was related to body size. These findings signal potential adverse trends in weight gain and BP trends for children growing up in the context of a country that has recently undergone rapid economic transition
Simple technique for evacuation of traumatic subcutaneous haematomas under tension
BACKGROUND: Traumatic subcutaneous haematomas are common cases in the accident and emergency department. Occasionally, urgent evacuation is required to prevent skin necrosis. METHODS: We present a simple and safe technique, based on a principle similar to liposuction to evacuate traumatic subcutaneous haematomas under tension. Instruments readily available in the accident and emergency department are used without the need of general anaesthesia. RESULTS: The technique was performed in six cases without complication such as infection or re-collection of the haematoma under tension. We present two typical scenarios where urgent evacuation was indicated and the technique performed. CONCLUSION: The technique is useful as an urgent and safe procedure in the accident and emergency department setting
Impact of remittances on economic growth in developing countries: The role of openness
The paper examines the empirical relationship between remittances and economic growth for a sample of 62 developing countries over the time period 1990–2014. Remittances seem to promote growth only in the ‘more open’ countries. That is because remittances are in themselves not sufficient for growth. The extent of the benefit depends on domestic institutions and macroeconomic environment in the receiving country. Unlike the ‘less open’ countries, ‘more open’ countries have better institutions and better financial markets to take advantage of the remittances income and channelise them into profitable investments which, in turn, accelerates the rate of economic growth in these countries.N/
Social network analysis predicts health behaviours and self-reported health in African villages.
The provision of healthcare in rural African communities is a highly complex and largely unsolved problem. Two main difficulties are the identification of individuals that are most likely affected by disease and the prediction of responses to health interventions. Social networks have been shown to capture health outcomes in a variety of contexts. Yet, it is an open question as to what extent social network analysis can identify and distinguish among households that are most likely to report poor health and those most likely to respond to positive behavioural influences. We use data from seven highly remote, post-conflict villages in Liberia and compare two prominent network measures: in-degree and betweenness. We define in-degree as the frequency in which members from one household are named by another household as a friends. Betweenness is defined as the proportion of shortest friendship paths between any two households in a network that traverses a particular household. We find that in-degree explains the number of ill family members, whereas betweenness explains engagement in preventative health. In-degree and betweenness independently explained self-reported health and behaviour, respectively. Further, we find that betweenness predicts susceptibility to, instead of influence over, good health behaviours. The results suggest that targeting households based on network measures rather than health status may be effective for promoting the uptake of health interventions in rural poor villages.This work was supported by N.W.O. grant #W07.68.116 to Professor Erwin Bulte.This is the final version, originally published by PLOS at http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0103500
Differences in human plasma protein interactions between various polymersomes and stealth liposomes as observed by fluorescence correlation spectroscopy
A significant factor hindering the clinical translation of polymersomes as vesicular nanocarriers is the limited availability of comparative studies detailing their interaction with blood plasma proteins compared to liposomes. Here, polymersomes are self-assembled via film rehydration, solvent exchange, and polymerization-induced self-assembly using five different block copolymers. The hydrophilic blocks are composed of anti-fouling polymers, poly(ethylene glycol) (PEG) or poly(2-methyl-2-oxazoline) (PMOXA), and all the data is benchmarked to PEGylated “stealth” liposomes. High colloidal stability in human plasma (HP) is confirmed for all but two tested nanovesicles. In situ fluorescence correlation spectroscopy measurements are then performed after incubating unlabeled nanovesicles with fluorescently labeled HP or the specific labeled plasma proteins, human serum albumin, and clusterin (apolipoprotein J). The binding of HP to PMOXA-polymersomes could explain their relatively short circulation times found previously. In contrast, PEGylated liposomes also interact with HP but accumulate high levels of clusterin, providing them with their known prolonged circulation time. The absence of significant protein binding for most PEG-polymersomes indicates mechanistic differences in protein interactions and associated downstream effects, such as cell uptake and circulation time, compared to PEGylated liposomes. These are key observations for bringing polymersomes closer to clinical translation and highlighting the importance of such comparative studies
Variation in antral follicle counts at different times in the menstrual cycle: does it matter?
Antral follicle count (AFC) variation was examined across the menstural cycle and its effect on clinical management assessed. In 79 women, AFC was documented in early (iAFC) and late follicular phase (sAFC). Absolute agreement between iAFC and sAFC and agreement for classification into categories of risk of extremes of ovarian response were examined. Ovarian stimulation protocols designed with iAFC and sAFC, and the predictive value of iAFC and sAFC for extremes of ovarian response, were compared in women undergoing ovarian stimulation. Significant differences were found between iAFC and sAFC (16 [IQR 9-24] versus 13 [IQR 7- 21]; P = 0.001), with moderate agreement for the classification into at risk of extremes of response (k = 0.525). Agreement for protocol selection based on either AFC (k = 0.750) and starting gonadotrophin dose was good (concordance correlation coefficient 0.970 [95% CI 0.951 to 0.982]). Predictive value for iAFC and sAFC was maintained for poor ovarian response and risk of ovarian hyperstimulation syndrome (OR 0.634 [0.427 to 0.920], 0.467 [0.233 to 0.935]) and (OR 1.049 [0.974 to 1.131], 1.140 [1.011 to 1.285]). Across the cycle, AFC varies but does not significantly affect ovarian stimulation protocol design and prediction of extreme ovarian response
Essential irrigation and the economics of strawberries in a temperate climate
Strawberries are a high value crop in the UK soft fruit sector, with the majority of production grown at field-scale and under protected (polytunnel) conditions. Despite its importance to the rural economy, there is surprisingly little published scientific evidence on the economics of irrigated strawberry production and the value of water in this horticultural sector. A survey of growers, supplemented by secondary data and industry sources, shows considerable variation in key physical and financial performance indicators, both within and between different strawberry production systems, as well as evidence of good practice. Water application depths ranged widely from 800 to over 2000 m3 ha−1 according to grower and crop variety. Irrigation costs typically range between £1.30 and £2.50 m−3 of water applied, highest where storage reservoirs and public water supplies are used. The average value of irrigation water for strawberry net of costs was about £6 m−3, much higher than for field crops such as potatoes. The importance of a reliable water supply to support irrigated strawberry production is highlighted. Climate change and growing pressures on water resources are likely to force a greater interest in irrigation economics in the soft fruit sector, especially in the face of restrictions on summer abstraction and rising competition and charges for using public water supply
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